# Phy 101 Lab 9

Topics: Resistor, Electric current, Ohm's law Pages: 3 (568 words) Published: April 3, 2014
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Electrical Components and Circuits
Course: PHY101

Purpose: The purpose and objectives of this lab was to be able to draw completed electrical circuits using the correct symbols for selected electrical components, including batteries and diodes. Another focus was to calculate the proper resistance using Ohm’s law, use proper electrical currents and quantities, and lastly measure voltage and resistance in an electrical circuit using a multimeter. Materials:

Wire
Light Emitting Diodes (red, green, blue)
Alligator Chips
Resistors
Multimeter
9-volt battery

Procedures:
1. With the components provided in the lab kit, “build” the DC series circuit. 2. Using the resistors provided, that limits the current to less than 20 ma, use the multimeter to measure the voltage drops across each component in the circuit. 3. When using the multimeter to measure, start with the highest scale and work down to the scale that provides the most readable voltage value. Record the data found in an Excel spreadsheet. 4. Use the voltage drops across the resistor and the value of the resistor to calculate the current flow through the resistor. ( the same current flows through the LED.) 5. With Excel and the values found for the voltage across the LED and current through the LED, plot a graph to determine if the LED obeys Ohm’s Law.

Data:

Calculations:
LED Resistor Value:
R = (VS - VL) / I
Vs: supply voltage
VL: LED voltage
I: LED current
R: resistance of the resistor

Ohm’s Law:
R = V/I
V: voltage across the resistor
I: current through the resistor
R: resistance of the resistor

Results:

The plot of the current shows a straight, linear line. This determines that the LED obeys Ohm’s Law.

Conclusion:

This experiment allowed one to develop the knowledge and skill of creating a functional circuit by first learning about each electronic component that plays a role in...

References: Giancoli, D.C. (2006). Physics (6th ed.). Upper Saddle River: Pearson Prentice Hall.